Method of making colored artificial yarns and films



Patented Mar. 9, 1937 UNITED STATES METHOD OF MAKING COLORED ARTI- FICIAL YARNS AND FILMS William Whitehead, Cumberland, Md., assignor to Celanese Corporation of America, a. corporation of Delaware No Drawing. Application October 2'7, 1933 Serial No. 695,504

8 Claims.

This invention relates to the manufacture of a dye or dye-base which is non-corrosive to metal or metal alloys when it is applied to the formation of organic derivatives of cellulose filaments or films wherein the dye or dye-base is added to the solution from which the filaments are spun. This invention also relates to the manufacture of colored films or filaments which are formed with a color base that may or may not be topped with a color aid such as a pigment or a complementary color.

An object of the invention is to produce a dye or dye-base which is non-corrosive to the metals or metal alloys found in the system used in the spinning of filaments from organic derivatives of cellulose.

Another object of the invention is the production of a dye or dye-base that is economical to prepare, that can be used in the spinning solution for spinning synthetic filaments, that is compatible with the components of the spinning solution and that is commercially fast to light and acids.

Another object of the invention is the production of films or filaments having a fast deep shade of color. Other objects of the invention will be apparent from the following detailed description.

In the process of manufacturing filaments containing organic derivatives of cellulose, it is commercially impractical, without special precautions, to use in the spinning solution containing organic derivatives of cellulose in a solvent, nigrosine and induline dyes or dye bases in that they corrode the metal pumps, candles and spinnerets. Such dyes or dye-bases ordinarily reduce the life of said devices to such an extent that the whole spinning system becomes inoperative in a relatively few hours, say 6 to 8 hours.

I have found that by treating nigrosine and induline dyes or dye-bases with an alkali dissolved in a solvent that is a solvent for the dye or dye-base and for the alkali, the dye or dyebase is converted into a compound which is noncorrosive to metal and metal alloys. This is believed to be caused by the removal of the chlorine radicle from the compounds in the dye or dyebase and also by rearrangement of the molecular structure of certain of the components of the dye or dye-base. The dyes are composed of compounds that have a large molecular structure. They, therefore, probably retain the chlorine radicle even after a severe treatment with a heated alkali or an alkali in an aqueous solution, such as refluxing the mixture for as long as two days.

The treatment of these dyes with aqueous alkalies, even after refluxing for many hours, has apparently no effect in reducing the corroding power of these dyes and dye-bases. However, by treating them with a solvent for both the particular dye and also for the particular alkali used, even in the cold, the dyes are so converted that they are non-corrosive in the spinning solutions used in the spinning of organic derivative of cellulose foils, films or filaments. By using dyes treated according to this invention, no special precautions are necessary to prevent corrosion of the metal parts of a spinning system. by this invention spinning solutions may be made up containing as high as 8% of the dye or dye base on the weight of the organic derivatives of cellulose, which spinning solutions do not have any visible effect on the spinnerets, the candles or the pumps in the spinning system. Even when the spinnerets and pumps contain alloys of copper with zinc and iron, they are nevertheless unaffected by the dyes and dye-bases treated according to this invention.

Nigrosine and induline dyes and dye-bases treated according to this invention, as far as one is able to ascertain, lose none of their properties as dyes when they are used in connection with organic derivatives of cellulose. The color imparted to the organic derivatives of cellulose is as fast, as deep and of the same shade as the color imparted to the organic derivatives of cellulose by the corresponding dye prior to treatment.

According to my invention, I treat with an alcoholic solution of an alkali dyes or dye-bases formed by the reaction product of heating together nitrobenzene, aniline and aniline hydrochloride with iron or copper the products of this reaction being known as nigrosine dyes, or similar dyes made as the reaction product of equivalents of the above and which are known as induline dyes, these dyes having Color Index numbers between 859 and 869. The dyes or dye-bases formed from the above ingredients and equivalent ingredients although they have a neutral or alkaline reaction in an aqueous solution, nevertheless corrode metals and metal alloys when used in the presence of an organic derivative of cellulose, unless treated such as by refluxing for from 1 to 8 hours in an alcoholic solution of an alkali. However, it is found that the metal parts of the spinning system may be prepared by annealing or coating such that they will be resistant to the commercial nigrosine and induline dyes for long periods of time.

Dyes treated according to this invention may be added in percentages up to 8% to solutions containing organic derivatives of cellulose, from which filaments, foils or films are to be made, without reacting with the metal of the spinning system. The spinning solutions may contain besides the dye or dye-base and the organic derivatives of cellulose, materials which will act as cffect materials in the spun films or filaments.

Such effect materials may be pigments, filling materials, fire retardants, plasticizers, sizes and lubricants. Examples of fire retardants are beta 5 chlornaphthalene and tricresyl phosphate. EX-

amples of plasticizers are glycol and glycerol oleates and stearates. Examples of lubricants are olive oil and mineral oil. Examples of filling materials and pigments are metal oxides, powdered. metals, lamp black and logwood. Spinning solutions containing mixtures of commercial nigrosine or induline dyes, or 2. treated nigrosine or induline dye, organic derivatives of cellulose and any of the above efiect materials may be spun by either the wet or dry method of spinning commonly employed in the spinning of normal organic derivative of cellulose spinningsolutions.

The water-soluble dyes of the nigrosine and induline dye-bases that do not corrode the untreated metal parts of a spinning system may be formed by treating the nigrosine and induline dye-bases with an alcoholic solution of an alkali prior to sulphonating them and converting them into the sodium salts thereof. The water soluble dyes and dye-bases thus formed retain all their properties as dyes so far as their use in connection with organic derivatives of cellulose are concerned.

These dyes for the most part are partially soluble in acetone, acetone and ethyl alcohol, acetone and methyl alcohol and in other solvents used in spinning solutions of organic derivatives of cellulose. In such solvents and in the presence of the organic derivatives of cellulose, these dyes and dye-bases prior to treatment with alcoholic alkali give oii a hydrolyzed chlorine radicle which, by the above treatment, is removed from the dye.

These treated dyes, therefore, do not corrode the metals due to the presence of chlorine and also due to other changes in their molecular structure which may have taken place during their treatment by refluxing in the alcoholic solution of alkali.

The alcoholic alkali solutions for treating commercial nigrosine and induline dyes may be composed of sodium, potassium or any alkali or alkali earth metal hydroxides or mixtures of same in methyl, ethyl or other alcoholic solvents that are solvents for both the hydroxide and at least a part of the components of the dye. Thus, mixtures of potassium and sodium hydroxides may be dissolved in a mixture of methyl and ethyl alcohol to form the treating solution with which to convert the dye or dye-base into a non-corrosive dye or dye-base.

This invention is applicable to films formed from solutions containing dyestuffs other than those of nigrosine and induline. This invention is not limited to pretreated nigrosines and indulines but also includes the similarly treated dyestuifs of a similar constitution thereto containing bodies high in molecular weight which are derived from the organic hydrochlorides or those in which hydrochloric acid or chlorides are involved in their formation.

Colored foils, films or filaments that are fast to light and acids and that are of a deep appearing color may be formed by adding to the solution of organic derivative of cellulose from which they are formed from 1 to 5% of a pigment such as lamp black or logwood and about 2% of a nigrosine or induline dye, the percentage being based on the weight of the organic derivative of cellulose present. By this method the foils, films or filaments are impregnated with a solid opaque material which prevents the passage or" light therethrough, while the cellulose deriva tive surrounding the pigment is also colored, thereby deepening the appearance of the color.

Colored foils, films or filaments that are fast to light and acids and that are of deep shades such as navy blue, jet black, and brownish blacks may also be formed by adding to a spinning solution from 1 to 3% of a nigrosine dye and a complementary or topping color dye. For example, the jet black films or filaments may be made by adding to the spinning solution2% of nigrosine dye and 1% of metanitraniline yellow or other yellows such, for example,-as 2:4-dinitro, diphenylamine. The navy blue shade maybe made by employing a reduced amount of nigrosine (on the blue side) with a light blue as a complementary color. The reddish blacks may be formed by employing a reduced amount of nigrosine (on the red side) with a red dye as a complementary color.

Having described my invention, what I desire to secure by Letters Patent is:

l. The method of forming colored films, foils or filaments which comprises forming the same from a solution of an organic derivative of cellulose containing a dye selected from the group consisting of nigrosines and indulines, said dye being pretreated with an alcoholic solution of an alkali.

2. The method of forming colored films, foils or filaments which comprises forming the same from a solution of cellulose acetate containing a dye selected from the group consisting of nigrosines and indulines, said dye being pretreated with an alcoholic solution of an alkali.

3. The method of forming films, foils or filaments which comprises forming thesame from a solution of an organic derivative of cellulose containing a pigment and a dye selected from the group consisting of nigrosines and indulines that has been pretreated with an alcoholic solution of an alkali.

4. The method of forming films, foils or filaments which comprises forming the same from a solution of cellulose acetate containing a pigment and a dye selected from the group consisting of nigrosines and indulines that has been pretreated with an alcoholic solution of an alkali.

5. Spinning solutions comprising an organic derivative of cellulose and a dye, selected from the group consisting of nigrosines and indulines, which has been treated with an alcoholic solution of an alkali.

6. Spinning solutions comprising cellulose acetate and a dye, selected from the group consisting of nigrosines and indulines, which has been treated with an alcoholic solution of an alkali.

7. Spinning solutions comprising an organic derivative of cellulose, a pigment, and a dye, selected from the group consisting of nigrosines and indulines, which has been treated with an alcoholic solution of an alkali.

8. Spinning solutionscomprising cellulose acetate, a pigment, and a dye, selected from the group consisting of nigrosines and indulines, which has been treated with an alcoholic solution of an alkali.

WILLIAM WHITEHEAD. 

